Method and system for evaluating brightness values in sensor images of image-evaluating adaptive cruise control systems

• US 8,379,088 B2
• Filed: 08/28/2008
• Issued: 02/19/2013
• Est. Priority Date: 08/29/2007
• Status: Active Grant

• Current Assignee: Valeo Schalter und Sensoren GmbH (Valeo SE)
• Original Assignee: Valeo Schalter und Sensoren GmbH (Valeo SE)
• Inventors: Kuehnle, Andreas, Boon, Cathy
• Primary Examiner(s): Dalencourt, Yves
• Application Number:
  US12/674,920
• Publication Number:
  US 20110109744A1
• Time in Patent Office: 1,636 Days
• Field of Search: 348/148, 348/151, 348/159, 348/E3.018
• US Class Current: 348/148
• CPC Class Codes: B60W 40/072 Curvature of the road
• CPC Class Codes: B60W 40/076 Slope angle of the road
• CPC Class Codes: G06V 20/588 Recognition of the road, e.g. of lane markings; Recognition of the vehicle driving pattern in relation to the road

Abstract

A method and a system for evaluating sensor images of an image-evaluating adaptive cruise control system on a moving support, especially a vehicle which moves on a roadway, are disclosed. Irregularities, especially tar strips or tar joints on the roadway are evaluated due to their geometric shapes, their brightness, their contrast and/or their reflectivity to distinguish them from markings relating to the predetermined trajectory.

Claims

1. A method for evaluating sensor images of an image-evaluating surroundings-detection system on a carrier comprising a driver assistance system and which moves on a carriageway, the method comprising:

evaluating irregularities of a surface of the carriageway using a predefined range of fluctuation in width or length in a direction of movement of the carrier on the basis of at least one selected from the a group consisting of a shape, a geometric extent, a brightness, a contrast and a reflectivity of the irregularities; and

signalling an effect to which the irregularities are differentiated from markings relating to a predefined course of the carriageway; and

wherein the brightness irregularities consist of brightness values of pixels of the sensor image, and the brightness values are evaluated as irregularities of the surface of the carriageway to determine whether the brightness values of the pixels exceed a predefined range of variation in terms of a width and a length in a direction of movement of the carrier.

2. The method according to claim 1, wherein a deviation of more than 3 to 5 cm is registered as an upward transgression of the range of variation.

3. The method according to claim 1, wherein the brightness irregularities consist of brightness values of pixels of the sensor image, and the brightness values are evaluated as irregularities of the surface of the carriageway to determine whether the brightness values of the pixels exceed a predefined brightness value and/or contrast.

4. The method according to claim 3, wherein an upward transgression of the brightness value and/or contrast is registered when the sensitivity and the amplification drops below a predefined value during the evaluation of images of the pixels.

5. The method according to claim 1, wherein the brightness values of pixels of the sensor image are registered as irregularities of the surface of the carriageway if the pixels are darker than the surroundings at an acute angle of incidence of the light beaming into the image-evaluating surroundings-detection system.

6. The method according to claim 1, wherein the brightness values of pixels of the sensor image are registered as irregularities of the surface of the carriageway if a fluid transition, from a bright area to a dark area, is registered in a direction of movement of the carrier.

7. The method according to claim 1, wherein tar strips and tar joints which have been provided on the carriageway are registered as irregularities.

11. A computer program product stored on a non-transitory computer-usable medium, comprising computer-readable program instructions which, when the computer program product is executed on a microprocessor with an associated storage means, cause said microprocessor to carry out the method as claimed in claim 1.

8. An arrangement for evaluating sensor images of an image-evaluating surroundings-detection system on a carrier which has a driver assistance system, comprising:

at least one electronic camera contained in the image-evaluating surroundings-detection system, wherein the at least one camera is provided on a vehicle which acts as the carrier comprising a lane-keeping support system, wherein the at least one camera is configured to continuously register an area in front of the vehicle in a direction of travel of the vehicle on a carriageway;

a sensor image formed from the area registered by the at least one electronic camera, wherein the sensor image comprises pixels with brightness values and color values configured to depict the surroundings;

an evaluation device configured to evaluate irregularities of a surface of the carriageway using a predefined range of fluctuation in width or length in a direction of movement of the carrier on the basis of one selected from a group consisting of a shape, a geometric extent, a brightness, a contrast and a reflectivity of the irregularities of the surface, and to signal an effect to which the irregularities are differentiated from markings relating to a predefined course of the carriageway; and

wherein the brightness irregularities consist of brightness values of pixels of the sensor image, and the brightness values are evaluated as irregularities of the surface of the carriageway to determine whether the brightness values of the pixels exceed a predefined range of variation in terms of a width and a length in a direction of movement of the carrier.

9. The arrangement according to claim 8, further comprising one or more rearward looking cameras, wherein at least one of the rearward looking cameras detects an irregularity or a marking which is then verified with the at least one electronic camera, or the at least one electronic camera identifies the location of the irregularity or of the marking and verifies the latter with the at least one of the rearward looking cameras.

10. The arrangement according to claim 8, wherein at least one of the electronic cameras operates with a divided image, resulting in said electronic camera receiving a forward looking image and a rearward looking image with corresponding optics.